iPhone - 镜像从前面的相机拍摄的照片 [英] iPhone - Mirroring back a picture taken from the front camera

问题描述

当使用iPhone 4的前置摄像头拍摄照片时，拍摄的照片与您在iPhone屏幕上看到的照片相比较。如何恢复UIImage（而不是UIImageView）的屏幕视图，并能够像这样保存？

我试过：

  UIImage * transformedImage = [UIImage imageWithCGImage：pickedImage.CGImage scale：1.0 orientation：UIImageOrientationLeftMirrored]; 
 UIImageWriteToSavedPhotosAlbum（convertedImage，self，@selector（photoSaved：didFinishSavingWithError：contextInfo :)，nil）; 
  

然后将其放在屏幕上。

所以...如何恢复屏幕上的屏幕上视图？ UIImage（而不是UIImageView），并能够像这样保存？

我也试过这样：

  UIImage * pickedImage = [[info objectForKey：UIImagePickerControllerOriginalImage] retain]; 
 UIImage * transformedImage; 
 
 CGSize imageSize = pickedImage.size; 
 UIGraphicsBeginImageContextWithOptions（imageSize，YES，1.0）; 
 GContextRef ctx = UIGraphicsGetCurrentContext（）; 
 
 CGContextRotateCTM（ctx，3.14）; // rotate by 180°
 CGContextScaleCTM（ctx，1.0，-1.0）; // flip vertical 
 CGContextDrawImage（ctx，CGRectMake（0.0，0.0，imageSize.width，imageSize.height），pickedImage.CGImage）; 
 transformedImage = UIGraphicsGetImageFromCurrentImageContext（）; 
 
 UIGraphicsEndImageContext（）; 
  

但这只是一个黑色的图像。

 解决方案
 imageSize = pickedImage.size; 
 UIGraphicsBeginImageContextWithOptions（imageSize，YES，1.0）; 
 CGContextRef ctx = UIGraphicsGetCurrentContext（）; 
 CGContextTranslateCTM（ctx，imageSize.width，0.0）; 
 CGContextScaleCTM（ctx，-1.0，1.0）; 
 CGContextDrawImage（ctx，pickedImage.CGImage，CGRectMake（0.0，0.0，imageSize.width，imageSize.height））; 
 UIImage * transformedImage = UIGraphicsGetImageFromCurrentImageContext（）; 
 UIGraphicsEndImageContext（）; 
 UIImageWriteToSavedPhotosAlbum（convertedImage，self，@selector（photoSaved：didFinishSavingWithError：contextInfo :)，nil）; 
  

这是写出来的内存，没有编译器的帮助，请不要复制和粘贴。 ..

When using the front camera of the iPhone 4 to take a picture, the taken picture is mirrored compared with what you see on the iPhone screen. How may I restore the "on screen" view of the UIImage (not the UIImageView), and be able to save it like this ?

I tried :

UIImage* transformedImage = [UIImage imageWithCGImage:pickedImage.CGImage scale:1.0 orientation:UIImageOrientationLeftMirrored];
UIImageWriteToSavedPhotosAlbum (transformedImage, self, @selector(photoSaved:didFinishSavingWithError:contextInfo:), nil);

then putting it on screen. It is nearly the same as seen on screen, but the saved image is distorted.

So... How may I restore the "on screen" view of the UIImage (not the UIImageView), and be able to save it like this ?

I also tried this way :

UIImage* pickedImage = [[info objectForKey:UIImagePickerControllerOriginalImage] retain];
UIImage* transformedImage;

CGSize imageSize = pickedImage.size;
UIGraphicsBeginImageContextWithOptions(imageSize, YES, 1.0);
GContextRef ctx = UIGraphicsGetCurrentContext();

CGContextRotateCTM(ctx, 3.14);  // rotate by 180°
CGContextScaleCTM(ctx, 1.0, -1.0); // flip vertical
CGContextDrawImage(ctx, CGRectMake(0.0, 0.0, imageSize.width, imageSize.height), pickedImage.CGImage);
transformedImage = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

But that just gives a black image.

解决方案

The best way is to draw the image into a new context.

CGSize imageSize = pickedImage.size;
UIGraphicsBeginImageContextWithOptions(imageSize, YES, 1.0);
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(ctx, imageSize.width, 0.0);
CGContextScaleCTM(ctx, -1.0, 1.0);
CGContextDrawImage(ctx, pickedImage.CGImage, CGRectMake(0.0, 0.0, imageSize.width, imageSize.height));
UIImage *transformedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
UIImageWriteToSavedPhotosAlbum (transformedImage, self, @selector(photoSaved:didFinishSavingWithError:contextInfo:), nil);

This was written out of memory and without aid of a compiler, please don't copy and paste...

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